Curious too. Have been giving away "fart pillows" (don't know the name, like a flat balloon that you're supposed to hide under a chair seat) on my daughters birthday parties. It's been a blast so far :)
According to the site, it's 2 for $12.95 now, hopefully 50 would make it worthwhile with shipping and customs.
At the time, at least, 50 was $175 including US shipping, or $3.50 each.